For displaying myocardial infarct regions, magnetic resonance tomography has hitherto mainly been used. So-called cardio MR is today still the established standard for visualization of heart wall diseases, since, in this technique, numerous methods such as MR perfusion or wall movement analyses are available which permit functional examination of the heart muscle (myocardium). In MR perfusion, MR images are recorded with injection of contrast medium. This permits the visualization of the contrast enhancement in the myocardium which occurs during the first rapid circulation of the injected contrast medium (so-called first-pass enhancement). This exploits the fact that the infarct region is due, pathophysiologically, to a cell area in which the cell membranes are completely or at least partially damaged by inadequate supply of oxygen, for example because of coronary stenosis. The contrast medium accumulates in these damaged areas, such that these areas are identifiable in the images.
The damaged infarct regions can in principle also be detected in the time interval of the first-pass enhancement by computed-tomography images, by visualizing the infiltration of the contrast medium into the heart muscle. The accumulation of the contrast medium in the damaged areas of the myocardium is reflected by narrow, irregularly described regions in the CT images which are generally visualized in MPR display (MPR: Multi-Planar Reformatting). However, these regions in the myocardium can be visually detected only with great difficulty, partly because of the proximity to the heart cavities filled with contrast medium, the so-called blood pool, because this blood pool in the same way delivers the high contrast generated by the contrast medium.
The only possible way of using cardio CT data of this kind for detecting infarct regions in the myocardium hitherto involved elaborate manual analysis of the regions of the heart muscle in the image data, and manual entry of regions of interest into a list. Manual construction of the standardized long and short axes of the heart was also necessary. This kind of evaluation, however, is too time-consuming for routine use.
U.S. Pat. No. 6,628,743 B1 discloses a method for acquiring and analyzing cardiac data, in which CT image data of the heart are made available which were recorded at different times after an injection of contrast medium. The method involves a segmentation of the myocardium based on common segmentation algorithms such as threshold methods, edge detection or region growing, in order to analyze the contrast medium enhancement at different times after the injection of contrast medium in the myocardium. This therefore involves comparison of CT images recorded at different times. Enhanced pixels can also be displayed in color.
WO 2004/003851 A2 is concerned with the display of parietal movements in a deformable 3D object, for example the heart, by way of a single image. In one example in the document, 3D ultrasound image data of the left ventricle of the heart are made available in order to display corresponding wall movements of the left ventricle. The wall of the left ventricle is here segmented from the image data by a segmentation technique in which a so-called “simplex mesh model” is adapted to the wall profile. This model involves a surface which is represented in the form of a mesh and which is adapted to the profile of the left ventricle in the ultrasound image data. For this purpose, however, the wall profile must already be to some extent apparent in the image data.